论文部分内容阅读
目的 探讨脂质胞壁酸(LTA)诱导的延迟预适应对内皮细胞再复氧(H/R)损伤的作用,以及内源性一氧化氮(NO)参与保护机制的作用。方法 采用培养的人冠状动脉内皮细胞(HCAECs)在缺氧条件下培养 2h,然后在常氧条件下复氧培养 4h,模拟缺血 /再灌注损伤的模型。HCAECs在缺氧前 24h预先在含LTA(30或 300μg·L-1 )的培养基中培养 4h。用台盼蓝排斥法和培养基中乳酸脱氢酶(LDH)含量来评价内皮细胞损伤程度,比色法检测培养基中一氧化氮(NO)含量。并用RT PCR检测LTA预适应后(2-24)hHCAECseNOSmRNA的表达。结果 LTA预适应能显著减少台盼蓝排斥实验中的细胞死亡百分比,降低复氧末细胞培养液中LDH的含量。LTA预适应亦能显著增加HCAECs复氧末培养液中NO含量。LTA预适应的效应可被非选择性NOS抑制剂L 单甲基精氨酸(L NMMA, 100μmol·L-1 )所取消。在LTA预适应后 2和 4h,HCAECs的eNOSmRNA表达明显增加。结论LTA诱导的延迟预适应能显著减少HCAECs再复氧所致的细胞损伤和功能紊乱,eNOS产生的NO启动并介导了LTA保护内皮细胞的作用。
Objective To investigate the effect of delayed preconditioning induced by lipoteichoic acid (LTA) on endothelial reoxygenation (H / R) injury and the role of endogenous nitric oxide (NO) in the protection of endothelial cells. Methods Cultured human coronarial endothelial cells (HCAECs) were cultured in hypoxia for 2 hours and then reoxygenated for 4 hours under normoxic conditions to simulate the model of ischemia / reperfusion injury. HCAECs were cultured for 24 h in medium containing LTA (30 or 300 μg · L -1) 24h before hypoxia. The degree of endothelial cell injury was evaluated by trypan blue exclusion method and lactate dehydrogenase (LDH) content in culture medium, and the content of nitric oxide (NO) in culture medium was detected by colorimetry. The expression of hHCAECseNOS mRNA was detected by RT-PCR after LTA preconditioning (2-24). Results LTA preconditioning could significantly reduce the percentage of cell death in trypan blue exclusion test and decrease the content of LDH in reoxygenation end-cell culture medium. LTA preconditioning also significantly increased NO content in HCAECs reoxygenation medium. The effect of LTA preconditioning was abolished by the non-selective NOS inhibitor L-monomethyl-arginine (L NMMA, 100 μmol·L-1). At 2 and 4 h after LTA preconditioning, eNOS mRNA expression was significantly increased in HCAECs. Conclusions Delayed preconditioning induced by LTA can significantly reduce cell injury and dysfunction caused by reoxygenation of HCAECs. NO produced by eNOS can initiate and mediate the protective effect of LTA on endothelial cells.